commit 5335a8e6f8317ea3645227d139369f8931cdb299 Author: David Goulet <dgoulet@torproject.org> Date: Wed Feb 1 10:08:40 2017 -0500 Rename --enable-expensive-hardening configure option It is renamed to --enable-fragile-hardening. TROVE-2017-001 was triggerable only through the expensive hardening which is making the tor daemon abort when the issue is detected. Thus, it makes tor more at risk of remote crashes but safer against RCE or heartbleed bug category. Fixes #21290. Signed-off-by: David Goulet <dgoulet@torproject.org> --- changes/bug21290 | 7 +++++++ configure.ac | 29 +++++++++++++++++++++++++---- 2 files changed, 32 insertions(+), 4 deletions(-) diff --git a/changes/bug21290 b/changes/bug21290 new file mode 100644 index 0000000..2a8e845 --- /dev/null +++ b/changes/bug21290 @@ -0,0 +1,7 @@ + o Minor bugfixes (configure, autoconf): + - Rename the configure option --enable-expensive-hardening to + --enable-fragile-hardening. TROVE-2017-001 was triggerable only through + the expensive hardening which is making the tor daemon abort when the + issue is detected. Thus, it makes tor more at risk of remote crashes but + safer against RCE or heartbleed bug category. Fixes bug 21290; bugfix on + tor-0.2.5.4-alpha. diff --git a/configure.ac b/configure.ac index 3cddccc..1ae445b 100644 --- a/configure.ac +++ b/configure.ac @@ -145,8 +145,14 @@ dnl Others suggest '/gs /safeseh /nxcompat /dynamicbase' for non-gcc on Windows AC_ARG_ENABLE(gcc-hardening, AS_HELP_STRING(--disable-gcc-hardening, [disable compiler security checks])) +dnl Deprecated --enable-expensive-hardening but keep it for now for backward compat. AC_ARG_ENABLE(expensive-hardening, - AS_HELP_STRING(--enable-expensive-hardening, [enable more expensive compiler hardening; makes Tor slower])) + AS_HELP_STRING(--enable-expensive-hardening, [enable more fragile and expensive compiler hardening; makes Tor slower])) +AC_ARG_ENABLE(fragile-hardening, + AS_HELP_STRING(--enable-fragile-hardening, [enable more fragile and expensive compiler hardening; makes Tor slower])) +if test "x$enable_expensive_hardening" = "xyes" || test "x$enable_fragile_hardening" = "xyes"; then + fragile_hardening="yes" +fi dnl Linker hardening options dnl Currently these options are ELF specific - you can't use this with MacOSX @@ -772,14 +778,14 @@ m4_ifdef([AS_VAR_IF],[ TOR_TRY_COMPILE_WITH_CFLAGS(-fwrapv, also_link, CFLAGS_FWRAPV="-fwrapv", true) fi -if test "x$enable_expensive_hardening" = "xyes"; then +if test "$fragile_hardening" = "yes"; then TOR_TRY_COMPILE_WITH_CFLAGS(-ftrapv, also_link, CFLAGS_FTRAPV="-ftrapv", true) if test "$tor_cv_cflags__ftrapv" = "yes" && test "$tor_can_link__ftrapv" != "yes"; then AC_MSG_WARN([The compiler supports -ftrapv, but for some reason I was not able to link with -ftrapv. Are you missing run-time support? Run-time hardening will not work as well as it should.]) fi if test "$tor_cv_cflags__ftrapv" != "yes"; then - AC_MSG_ERROR([You requested expensive hardening, but the compiler does not seem to support -ftrapv.]) + AC_MSG_ERROR([You requested fragile hardening, but the compiler does not seem to support -ftrapv.]) fi TOR_TRY_COMPILE_WITH_CFLAGS([-fsanitize=address], also_link, CFLAGS_ASAN="-fsanitize=address", true) @@ -861,7 +867,7 @@ saved_CFLAGS="$CFLAGS" TOR_CHECK_CFLAGS(-fomit-frame-pointer) F_OMIT_FRAME_POINTER='' if test "$saved_CFLAGS" != "$CFLAGS"; then - if test "x$enable_expensive_hardening" != "xyes"; then + if test "$fragile_hardening" = "yes"; then F_OMIT_FRAME_POINTER='-fomit-frame-pointer' fi fi @@ -1960,4 +1966,19 @@ if test "x$asciidoc" = "xtrue" && test "$ASCIIDOC" = "none"; then done fi +if test "$fragile_hardening" = "yes"; then + AC_MSG_WARN([ + +============ +Warning! Building Tor with --enable-fragile-hardening (also known as +--enable-expensive-hardening) makes some kinds of attacks harder, but makes +other kinds of attacks easier. A Tor instance build with this option will be +somewhat less vulnerable to remote code execution, arithmetic overflow, or +out-of-bounds read/writes... but at the cost of becoming more vulnerable to +denial of service attacks. For more information, see +https://trac.torproject.org/projects/tor/wiki/doc/TorFragileHardening +============ + ]) +fi + AC_OUTPUT